1. Field
Example embodiments relate to a capacitor structure and a method of forming the same, and more particularly, to a capacitor structure for a semiconductor device and a method of forming the same.
2. Description of the Related Art
In general, a capacitor structure holds electrons therein and emits the electrons for operating an electronic circuit such as an integrated circuit in a semiconductor device. As the integration degree of the integrated circuit is increased, the size of unit cells are reduced in a semiconductor device and capacitance for operating the integrated circuit is increased.
A metal-insulator-metal (MIM) capacitor or a metal-oxide-metal (MOM) capacitor is usually used as the capacitor for the semiconductor device. In the conventional MIM capacitor including a dielectric layer or an insulating layer between lower and upper electrodes, the capacitance per unit area of the capacitor is improved by a) increasing the dielectric constant of the dielectric layer, b) by reducing the thickness of the dielectric layer or c) by increasing the contact area between the lower electrode and the dielectric layer and between the upper electrode and the dielectric layer. In the conventional MOM capacitor including a pair of parallel electrode structures facing each other, the parallel electrode structures extend in a vertical direction, to thereby improve the capacitance per unit area of the capacitor.
However, the cell size of the semiconductor device has been significantly reduced and the dielectric materials having large dielectric constant sufficiently compensating for the cell size reduction become difficult to obtain, and thus there has been in much difficulties for increasing the capacitance per unit area in a semiconductor device.